Capillary channel structure for dispense interface

Abstract

The invention is related to a dispense interface for a drug delivery device for delivering at least two drug agents, comprising at least two two-ended flow regulation structures and a confluence, wherein each flow regulation structure comprises a fluid inlet opening at a first end, wherein each flow regulation structure comprises a fluid outlet opening connected to the confluence at a second end of the respective flow regulation structure and wherein at least one of the two-ended flow regulation structures comprises a capillary fluid channel. The invention is further related to a drug delivery device for delivering at least two drug agents comprising a dispense interface of the aforementioned kind, to a method for delivering at least two drug agents through an injection means of a drug delivery device and to a method for manufacturing a dispense interface of the aforementioned kind.

The invention claimed is: 
     
       1. A dispense interface for a drug delivery device for delivering at least two drug agents, comprising:
 at least two flow regulation structures configured to connect to at least two fluid reservoirs; and 
 a confluence at which the at least two flow regulation structures meet, 
 wherein each flow regulation structure has a first end and a second end and comprises:
 a fluid inlet opening at the first end, the fluid inlet opening of each flow regulation structure configured to connect to a different one of the at least two fluid reservoirs, and 
 a fluid outlet opening at the second end connected to the confluence, 
 
 wherein one or more of the at least two flow regulation structures each further comprises a capillary fluid channel that ends at the confluence,
 each capillary fluid channel having a volume configured to contain a backflow from one or more others of the at least two flow regulation structures, and arranged in a meandering pattern on a plane perpendicular to a direction of fluid flow through an outlet of the confluence. 
 
 
     
     
       2. The dispense interface of  claim 1 , wherein each of the at least two flow regulation structures comprises a respective capillary fluid channel that ends at the confluence. 
     
     
       3. The dispense interface of  claim 1 , wherein at least one of the at least two flow regulation structures further comprises a valve. 
     
     
       4. The dispense interface of  claim 3 , wherein at least one of the at least two flow regulation structures comprises a sequential arrangement of the valve and the capillary fluid channel that ends at the confluence. 
     
     
       5. The dispense interface of  claim 1 , wherein the confluence is configured to permit flow to a holding chamber of the dispense interface. 
     
     
       6. The dispense interface of  claim 1 , wherein each of the at least two fluid reservoirs is in the form of a respective fluid cartridge, and wherein the dispense interface further comprises a stub around each fluid inlet opening at the first end of each flow regulation structure, wherein each stub is configured to receive a different one of the at least two fluid cartridges. 
     
     
       7. The dispense interface of  claim 1 , formed from at least two integral parts including:
 a first integral part comprising a proximal end of the dispense interface; and 
 a second integral part comprising a distal end of the dispense interface. 
 
     
     
       8. The dispense interface of  claim 7 ,
 wherein the first integral part comprises a first boundary surface of each capillary fluid channel and 
 wherein the second integral part comprises a second boundary surface of each capillary fluid channel. 
 
     
     
       9. The dispense interface of  claim 7 , wherein each capillary fluid channel is formed by a joining of the first integral part and the second integral part. 
     
     
       10. A drug delivery device for delivering at least two drug agents comprising a dispense interface according to  claim 1 . 
     
     
       11. The dispense interface of  claim 2 , wherein a first volume of a first capillary fluid channel of a first of the at least two flow regulation structures is less than a second volume of a second capillary fluid channel of a second of the at least two flow regulation structures. 
     
     
       12. The dispense interface of  claim 1 , further comprising a holding chamber extending in a longitudinal direction of the dispense interface and configured to receive a fluid flow from the outlet of the confluence.